Tank plug



April 1953 s. WOODWARD 2,636,514

TANK PLUG Filed Jan. 21, 1949 2 SHEETSSHEET 1 'llllllllll Q IN VEW TOR.I

' Wayward,

April 1953 v s. c. WOODWARD 2,636,514

TANK PLUG Filed Jan. 21 1949 F 5 Q; 473 g v 44? d9 niiiiiiiilmfl' 0 4/7% INVENTOR.

. v Woaagard Patented Apr. 28, 1953 UNITED STATES PATENT OFFICE 2Claims.

The invention relates to a new and useful tank plug and has referencemore particularly to a tank plug for use in temporarily closing threadedopenings in tanks, pipe lines, boilers and other vessels requiringhydrostatic or pneumatic internal pressure tests.

Ordinarily when a test is to be made on a tank or similar vesselthreaded iron plugs, to which has been applied a sealing medium such aswhite or red lead, are screwed into all but one opening by the use of awrench or similar tool. The remaining opening has a pressure line andgauge connected thereto for forcing a fluid under pressure into the tankto ascertain whether the seams and rivets will hold a preselectedpressure. Frequently the plugs blow out, causing damage to the tank andsometimes injury to the workmen. Also considerable loss of valuableworking time results from frozen plugs, entailing additional expense fortheir removal. All of these disadvantages are overcome by the use of thepresent tank plug and accordingly an object of the invention is toprovide a tank plug for temporarily closing the openings in a tank orthe like, which will not require the use of a sealing compound andwherein the plug will not freeze to the tank.

. Another object of the invention is to provide an improved tank plug ofsimple construction and one that can be readily and easily applied orreleased entirely by hand so as not to require tools of any kind.

Another object of the invention is to provide a tank plug for use intesting tanks and the like which will form a primary seal around theopening into which the plug is threaded.

A more specific object is to provide a tank plug which will provide aprimary seal around the opening into which the plug is threaded and alsoa secondary seal to prevent leakage of pressure along the stem of thedevice.

Another object is to provide a tank plug of the character described towhich a hose or similar conduit means can be connected for directcommunication with the interior of the vessel being tested and which canalso be used to gradually relieve the pressure in the tank prior toactual removal of the device.

With these and various other objects in view,

the invention may consist of certain novel features of construction andoperation, as will be more fully described and particularly pointed outin the specification, drawings and claims appended hereto.

In the drawings which illustrate an embodiment of the invention andwherein like reference characters are used to designate like parts-Figure 1 is a sectional view of a portion of a tank in the region of aflanged opening showing the tank plug of the invention inserted andthreaded in the opening and illustrating the arrangement of the severalparts prior to scaling the opening;

Figure 2 is a view similar to Figure 1 but showing the several parts ofthe tank plug in operative sealing relation with the flange of thethreaded opening;

Figure 3 is a horizontal sectional view taken substantially along line3-3 of Figure 1, looking in the direction of the arrows;

Figure 4 is a horizontal sectional view taken substantially along line44 of Figure 1, looking in the direction of the arrows;

Figure 5 is a vertical sectional view showing a modified form of tankplug coming within the invention;

Figure 6 is a sectional view similar to Figure 5 but showing the severalparts of the tank plug in sealing relation with the flange of thethreaded opening; and

Figure '7 is a horizontal sectional view taken substantially along line1--1 of Figure 5.

Referring to the embodiment of the invention selected for illustrationin Figures 1 and 2, the numeral 5 indicates a wall of a tank, boiler orsimilar vessel having one or more openings leading to the interior ofthe tank. One of such openings is shown at 6 bordered by a flange Ihaving the internal threads 8 on the wall of the opening.

The tank plug includes a sealing member 9 in the form of a disc orplate, the periphery of which may be knurled or otherwise roughened, ifdesired, and which has a diameter greater than the opening 6. On theunder side or inner face of said disc or plate an annular groove Ill isformed to receive and hold the gasket H of rubber or other appropriatecompressible material. An opening 12 is provided centrally of the disc 9and said opening is surrounded by an annular seat 13, preferablyV-shaped in cross section, and which seat is located in the outer end ofthe hub portion I 4 of said disc. The central opening I2 in the disc 9receives the stem l5 and ac cordingly the disc is rotatably mounted onthe stem and has slidahle movement to a limited extent with respectthereto. The stem 15 is integral with the screw plug or threaded memberI 6 formed on the depending end of the stem, and said stem isadditionally provided with a bore H extending from the inner face of thescrew plug to the outer end of the stem. The screw plug 15 is preferablyof such size that it overlaps the gasket H to a slight extent, or, inother words, the diameter of the gasket II is such that it will coactwith the flange surrounding the threaded opening for sealing the openingas will be better understood as the description proceeds. One or morepressure relief openings l8 are located in the screw plug I 6 forgradually relieving the pressure from within the tank when the sealformed by the gasket H is released. 7

On the outer end of stem a knob or handle I9 is mounted, the same havinga bore 26 which aligns with bore H to form a passageway from one end tothe other of the screw plug, stern and knob assembly. The knob l9includes a sleeve 2! having interfitting relation with the stem andwhich is secured to the stem by pins 22. The lower depending end of saidsleeve 2| is fashioned into annular protrusion which may be angular er vshapec cross section, forming a valve element 23 for cooperation withseat us.

When the device is to be used merely as a closure, the passagewayconsisting of bores i7 and 29 and also the relief openings l8 'areeliminated but one tank plug of a set should be constructed as shown inFigures 1 and 2 in order to provide for the delivery to the tank of apressure fluid for testing purposes and for the gradual release or thepressure fluid upon completion of the test. Figures 5 and 6 illustratethe closure type of plug wherein the axial extending passageway andpressure relief openings have been ornitted. The knob it may havethreads 24 or equivalent means at'the outer ens of the bore 28 for theconnection or a hose, gauge, plug or the like, depending upon theparticular manner in which the present tank plug is to be 'used.

In operation of the present device the screw plug It is screwed into athreaded opening such as E3 by grasping the knob l9 and rotating it inthe proper direction; As the threaded screw plug enters the opening ithas movement in an axial direction toward the flange I, and accordinglythe disc or plate 9 and the gasket H are also moved toward the flangeand which continues until the resilient gasket H contacts the outer faceor shoulder 25 of the flange. Continued screwing in of the screw plug I8will effect contact between the annular valve element 23 and the seat 53provided therefor so that the interfittihg engagement which these partshave eiiectively seals the stern, preventing leakage of the pressurefluid along the stem. Further screwin oi the screw plug 16 will applypressure to the disc or plates and thus to the resilient gasket H toforce the gasket into sealing engagement e the name compressing itsufficiently to insure a tight seal, as shown in Figure 2. Uponcompletion oithe above operation a conduit is then connected to thedevice by means of the threads 25 for delivering a fluid to the tank orvessel being tested and which fluid is delivered through the passages 20and H until the desired or preselected pressure is attained.

At the end of the test the tank plug can be removed by rotating knob H3in a direction to screw the screw plug it outwardly and by performingthis operation slowly the pressure fluid is allowed to gradually escapesince the pressure on sealing gasket H gradually removed. It will beseen that the chamber within said gasket 1 l is in communicatien withthe interior of the tank by ineans of openings 18. As soon as the tankpressure is reduced suiiiciently so that there is no further danger tothe operator, the screw plug I8 is removed from its threaded opening andthe same is ready for further use.

5 Figures 5, 6 and 7 illustrate a type of tank plug wherein the passagesll and 28 and the relief openings 58 have been eliminated. Such a tankplug is used only to close and seal an opening and with respect to sucha plug it will be understood that the tank pressure should be releasedor partially reduced at some other place, preferably by means of a plugsuch as shown in Figures 1 and 2.

The wall 35, Figures 5 and 6, may comprise the wall of a boiler, tank,pipe or other vessel having any number of openings leading to theinterior of the vessel. One of such openings is shown at 35 bordered bya flange 3'! having internal threads 38 on the wall of the opening. Thedevice of the invention for closing and sealing such a threaded openingessentially includes a sealing member the form of a disc or plate, theperiphery of which may be knurled or otherwise rough ned. It will beobserved that the disc as has a diameter greater than the opening 36 andlikewise the annular groove it on the unders'cle or inner of the discalso has a larger icter the. the opening for receiving and the gasket itof .ibber or other appropriate compressible material. The opening d2centrally of the disc receives the stem 15 integral proiecting centrallyfrom the screw plug 55. The annular seat E3; i -shaped in formation, isformed in the top surface of the hub portion it. The handle or knob 48is provided with a depending sleeve El having interrelation with theprojecting portion of the stern and being secured to said portion of thestem by the pin 52. Zlhe lower depending end of said sleeve 5! isfashioned into an annular protrusion which may be angular or V-shaped incross section to form a valve element 53 for cooperation with seat G3.

The tank plug closure and seal of Figures 5 and 6 has operation which issimilar in most respects to that as described with respect to the plugof Figures 1 and 2.

The screw plug 43, stern 15, and handle 49 are essentially one unit sothat rotation of the handle ill will rotate the screw plug 66 to efiectthreaded engagement with the Walls of the openin; This screwing of theplug it will result n axial movement of the unit toward the opening andaccordingly the disc 38 and gasket ll vll have similar movement sincethe disc is ro- When the gasket 3! contacts the to contact with theprotrusion o; The interengaging relation which these parts have witheach other effectively seals the stern, preventing leakage pressurealong the stem. As the screw plug lfi is threaded farther into theopening additional pressure is applied to gasket ll securely seatingthis gasket on flange whereby to provide a seal in surrounding relationwith the opening.

From the foregoing it will be apparent that an e ceedingly simple andeffective tank plug is provio'ed for closing and sealing threadedopenings in tanks and similar vessels and particularly where saidvessels are submitted to hydrostatic or pneumatic internal pressuretests. The test plug of the invention can be easily and quickly appliedor removed and an important advantage resides in the fact that saidoperations do not require tools or any kind nor does the screw plugrequire a sealing medium such as white lead customarily used withdevices of this kind as heretofore constructed.

This application is a continuation-in-part of my copending applicationSerial No. 759,765, filed July 9, 1947, now abandoned, and entitled TestPlug Cap.

The invention is not to be limited to or by details of construction ofthe particular embodiment thereof illustrated by the drawings, asvarious other forms of the device will of course be apparent to thoseskilled. in the art without departing from the spirit of the inventionor the sco e of the claims.

What is claimed is:

1. A test plug cap comprising a screw plug for threaded engagement witha flange surrounding an opening, a stem projecting from said screw plug,a disc carrying a gasket to engage the flat exposed face of the flange,said disc being loosely mounted on said stem whereby the latter mayrotate while the disc remains stationary and also move longitudinallythrough the disc when the gasket initially contacts the flange, anannular valve seat in the outwardly disposed surface of the discadjacent the joint between said disc and the stem, a knob provided witha sleeve secured to the outer end of the stem, and an annular valve plugon the inner end of said sleeve to engage said valve seat for sealingthe joint between said disc and stem and cause said disc to movelongitudinally with the stem for compressing the gasket.

2. The tes plug cap of claim 1 wherein a passage-way extends through thescrew plug and stem axially of the latter.

STERLING C. WGODWARD.

References Qiterl in the file of this patent UNITED STATES PA'IENTS2,358/i3 l Young Sept. 19, 1944

